AS Grammatika is a sans serif typeface inspired by both Helvetica and DIN. The designer describes it as a sturdy, low contrast, geometric font. It's hard to disagree with that after using this sans serif font download. The neat lines and five font weights make AS Grammatika one of the top Helvetica alternatives.
CA Saygon Text is both professional and playful. It's also the perfect sans serif font download if you want to experiment. That's because it comes with seven weights and five different stylistic sets. It also supports Cyrillic characters, as well as other languages.